Zinc Alloy Zamak 7
ASTM Zamak 7 · UNS Z33523
Zamak 7 is a high-purity, low-magnesium version of Zamak 3 (Z33523, AG40B, Mazak 7) made from special high-grade zinc with tight limits on lead, cadmium and tin.
Values for the As Cast condition
Zamak 7 tempers and conditions
Zamak 7 is supplied in 2 conditions, soft to hard. As Cast is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Aged / stabilized | Use these de-rated numbers for long-life design or when castings are dimensionally stabilized before precision machining. | 195 | 255 | 16 | 72 HB | 27 % IACS |
As CastDefault hot-chamber die cast, as-manufactured | Standard supply condition for Zamak 7 hot-chamber die castings — pick for thin-wall, high-ductility, plate-quality parts. | 210 | 283 | 13 | 80 HB | 27 % IACS |
What is Zamak 7?
Zamak 7 is a high-purity, low-magnesium version of Zamak 3 (Z33523, AG40B, Mazak 7) made from special high-grade zinc with tight limits on lead, cadmium and tin. Lower magnesium and controlled impurities give the best fluidity and thin-wall fill in the family, with as-cast values near 210 MPa yield, 283 MPa tensile, 13% elongation and 80 HB, and a machinability rating of 80; it is supplied as die castings and aged parts. Ductility is the highest of the Zamaks but strength is the lowest, service is limited to about 95 °C, and it is not weldable. Choose Zamak 3 when the tighter chemistry and its cost are not required. Zamak 7 has a density of 6.6 g/cm³ (0.238 lb/in³), lighter than 64% of zinc alloy grades. It melts at 381°C (718 °F). Zamak 7 has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 283 MPa (41 ksi) — stronger than 57% of zinc alloy grades. Elongation at break is 13% and the elastic modulus is 96 GPa (13.9 Msi).
What is Zamak 7 used for?
- Plated decorative parts
- Cosmetic cases
- Thin-wall electronic housings and shields
- Nameplates and emblems
- Precision hardware and trim
- Small connector and hinge components
Advantages
- Polishes to a fine finish — 85/100, better than 89% of zinc alloy grades
Zamak 7 properties
Typical room-temperature values for Zamak 7-As Cast; bars are the position among zinc alloy grades.
Physical3
Zamak 7 has a density of 6.6 g/cm³ (0.238 lb/in³), lighter than 64% of zinc alloy grades. It melts at 381°C (718 °F).
Mechanical13
Zamak 7 has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 283 MPa (41 ksi) — stronger than 57% of zinc alloy grades. Elongation at break is 13% and the elastic modulus is 96 GPa (13.9 Msi).
Thermal6
Zamak 7 is rated for continuous service to 95°C (203 °F). It conducts heat at 113 W/m·K (65.3 BTU/hr·ft·°F), better than 57% of zinc alloy grades. Thermal expansion is 27.4 µm/m·K (15.2 µin/in·°F).
Electrical3
Zamak 7 conducts electricity at 27 % IACS, worse than 57% of zinc alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), better than 79% of zinc alloy grades.
Sustainability4
Producing a kilogram of Zamak 7 takes about 53 MJ of energy and emits 3.5 kg of CO₂ — less than 68% of zinc alloy grades. Typical recycled content is 25%.
Manufacturability8
Zamak 7's machinability is very good (80/100, better than 64% of zinc alloy grades); weldability poor (15/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the zinc alloy family
Yield strength against density for every zinc alloy grade FabDigit runs. Zamak 7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Zamak 7
Is Zamak 7 easy to machine?
Machines very freely with sharp carbide or HSS tools, high speed and light feed; no cutting fluid strictly needed, but avoid built-up edge with polished rake faces.
Can Zamak 7 be welded?
Not weldable in practice — join by soldering, adhesive bonding, self-tapping screws, staking or press-fit inserts.
Can Zamak 7 be formed, bent or molded?
Hot-chamber die casting at ~410–430 °C melt; the low-Mg chemistry gives the best fluidity of the Zamak family for 0.4–0.8 mm walls, but demands SHG zinc and tight impurity control (Pb/Cd/Sn) to avoid intergranular corrosion.
Manufacturability
The process limits FabDigit's quote engine applies to Zamak 7. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent80 / 100 |
|---|---|
| Cutting speed (rough / finish) | — / — |
| Minimum wall | — |
| Minimum internal radius | — |
| Drill depth limit | |
| Best surface (machined / polished) | Ra — / — |
| Hardenable after machining | — |
Zamak 7 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Al | 3.5 – 4.3 | 4 |
| Mgdeliberately low vs Zamak 3 for fluidity and ductility | 0.01 – 0.02 | 0.01 |
| Niadded to offset low Mg and suppress intergranular corrosion | 0.01 – 0.02 | 0.01 |
| Cuimpurity limit | ≤ 0.25 | 0.05 |
| Fe | ≤ 0.08 | |
| Pbmax, tighter than Zamak 3 | ≤ 0 | |
| Cd | ≤ 0 | |
| Sn | ≤ 0 | |
| ZnSpecial High Grade 99.99 % Zn base | balance |
What surface finishes work on Zamak 7?
Excellent substrate for bright Cu-Ni-Cr plating, chromate/trivalent passivation, powder coat and e-coat; polish or vibratory finish before plating — never anodize.
Surface treatments FabDigit runs on zinc alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Zinc Alloy Zamak 7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- Z33523
- ASTM
- AG40B
- Trade names
- High Purity ZamakMazak 7
How much does Zamak 7 cost?
Zamak 7 is a standard-cost zinc alloy ($$), cheaper than about 81% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Zamak 7 — frequently asked
What is Zamak 7 used for?
Zamak 7 is typically used for plated decorative parts, cosmetic cases, thin-wall electronic housings and shields, nameplates and emblems, precision hardware and trim and small connector and hinge components. In short: plating-grade die-cast zinc.
What is the yield strength of Zamak 7?
Zamak 7 has a typical yield strength of 210 MPa (30.5 ksi) and a tensile strength of 283 MPa (41 ksi) — stronger than 57% of zinc alloy grades. Strength varies by condition: see the 2 listed tempers.
Is Zamak 7 easy to machine?
Yes — machinability is rated very good (80/100, better than 64% of zinc alloy grades). Machines very freely with sharp carbide or HSS tools, high speed and light feed; no cutting fluid strictly needed, but avoid built-up edge with polished rake faces.
Can Zamak 7 be welded?
Not readily — weldability is rated poor (15/100). Not weldable in practice — join by soldering, adhesive bonding, self-tapping screws, staking or press-fit inserts.
What surface finishes work on Zamak 7?
Excellent substrate for bright Cu-Ni-Cr plating, chromate/trivalent passivation, powder coat and e-coat; polish or vibratory finish before plating — never anodize.
Can Zamak 7 be formed, bent or molded?
Hot-chamber die casting at ~410–430 °C melt; the low-Mg chemistry gives the best fluidity of the Zamak family for 0.4–0.8 mm walls, but demands SHG zinc and tight impurity control (Pb/Cd/Sn) to avoid intergranular corrosion.
What is the maximum service temperature of Zamak 7?
Zamak 7 is rated for continuous use to about 95°C (203 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Zamak 7 As Cast and Zamak 7 Aged?
As Cast is the default condition — standard supply condition for Zamak 7 hot-chamber die castings — pick for thin-wall, high-ductility, plate-quality parts. Aged: use these de-rated numbers for long-life design or when castings are dimensionally stabilized before precision machining. Yield strength is 210 MPa in As Cast versus 195 MPa in Aged.
How much does Zamak 7 cost?
Zamak 7 is a standard-cost zinc alloy ($$), cheaper than about 81% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in Zamak 7?
Yes — Zamak 7 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B86 — Standard Specification for Zinc and Zinc-Aluminum (ZA) Alloy Foundry and Die Castings (Alloy AG40B / UNS Z33523) — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Zinc and Zinc Alloys) — ASM International (1990)
- NADCA Product Specification Standards for Die Castings — Zinc Alloys — North American Die Casting Association (2020)
- European Zinc Die Casters Association / Eastern Alloys Zamak alloy data — EZDA / Eastern Alloys (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.